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Previous Next The best candle and soap tips online! 325 324 TECHNICAL TREATISE ON SOAP AND CANDLES. into the soap pat) u-ith 250 gallons of potash lye, containing 250 pounds of dry caustic potash. Heat being applied to the pan, the mixture froths up very much as it approaches the boiling temperature, but is prevented from boiling over by being beaten down on the surface. Should it soon subside into a doughy-looking paste, it is to be inferred that the lye has been too strong. Its proper appearance is that of a thin glue. There should now be introduced about 42 gallons of a stronger lye, containing 55 pounds of potash, and after a short interval an additional 42 gallons; and thus successively till nearly 600 such gallons have been added in the whole. After sufficient boiling to saponify the fats, the proper quality of soap will be obtained, amounting in quantity to 6400 pounds, from the above quantities of materials. SECTION XIV. THE FABRICATION OF SOAPS (CONCLUDED). SlLICATED AND OTHER FlLLED SOAPS. THE filling and the sophistication of soaps i3 conducted to a greater or less extent in all business centres, and when the materials used are harmless and do not detract from the detersive power of the soap, they may be somewhat excused from that censure which all adulterations should receive. The materials generally used are water, soluble glass, dextrine, starch, clay, silica, sand, salt, etc., and there are many common soaps made from oft'al fat, bones, etc., in which are retained the many impurities natural to these substances. In regard to water it may be stated that the soaps made from cocoa-nut oil have the property of absorbing large quantities of water, without essentially losing thereby their hardness. This property the cocoa-nut oil transfers also to the soaps in which, in combination with other fats, it appears. The common soaps contain 35 to 50 per cent, of water, but there are some cocoa-nut oil soaps in the market, which contain as much as 75 per cent, of water. Such soaps shrink greatly in drying, and are covered—when they contain an overplus of alkali—-with a crust of fine white crystals. Since the cocoa-nut oil soaps are not separated even by greatly concentrated solutions of culinary salt, they may be impregnated with a large amount of salt water, without injuring their exterior appearance in the least. This may also be done to a less extent with soaps which are fabricated with cocoa-nut oil and other fats. In relation to this, the action of the different soaps is this: pure cocoa-nut oil soaps bear a great deal of salt; those of palm oil very little, and those of olive oil and tallow no salt at all. 326 TECHNICAL TREATISE ON SOAP AND CANDLES. THE FABRICATION OF SOAPS. 327 For filling these soaps there are applied, besides water and culinary salt, starch, offals (bones and greaves), chalk, clay, barytes, pumice stone, sand, soluble glass, and carbonate of soda. Of these substances, chalk is beyond dispute the very worst, because it does not merely make the soap thin, but in a great measure entirely destroys it, and causes it to be inefficient. Common Cocoa-nut Oil Soaps.—1000 kilog. (2200 lbs.) cocoa-nut oil are boiled with 1660 kilog. (3652 lbs) of a 7.5 per cent, caustic soda lye into a clear paste and filled with 1000 kilog. of a salt solution of 22° B. The frames must be well greased, because the soap is very thin, and scarcely combines. It may be marbled in the frames, with some vermilion or ultramarine, and perfumed with essential oils. Common Filled Rosin Soaps:— 1000 kilog. crude palm oil. 1000 " cocoa-nut " 1000 " rosin. 110 kilog. (242 lbs.) caustic soda. 112.5 " (247.5 " ) " " 104.0 " (228.8 " ) " " The soda is applied as a lye of 20° B. = 10.677 per cent., and hence uses ^A^l^ „ 3060 kilog. (6732 lbs.) = 2240 litres (593 gals.), which, added in three portions, is boiled until the potash shows but a slight " touch." The boiling is continued until the paste becomes thick, and after cooling off upon the spatula becomes firm. When in the'frames, 50 to 75 kilog. (110 to 165 lbs.) of a solution of sulphate of potash of 20° B. may be stirred in, which must be continued until the soap becomes tolerably cool, stiff and thick. The frames should not hold more than 200 to 250 kilog. (440 to 550 lbs.) of soap, and not exceed 60 centimetres (23.62 inches) in height. They can be also filled with clay, using for each frame 15 to 20 kilog. (33 to 44 lbs.). The stirring must be continued until the crutch draws furrows, and upon the surface partly dry spots make their appearance. Sometimes a solution of potash is stirred into the frames, i. e., to 200 kilog. (440 ll)s.) add 15 to 20 kilog. solution of 20° B., which makes the same very plastic. Soluble Glass Soap (Silicated Soap).—The manufacture of soluble glass soap became a real necessity when, some years ago, rosin became so expensive on account of the war, that it could no longer be used for making soaps, and manufacturers were compelled to substitute other ingredients. The directions for making this soap vary, principally as to the.quantity of soluble glass which is to be incorporated into a soap, and which is from 25 to 60 per cent. The method of manufacture consists in adding to the hot soap paste the desired quantity of soluble glass, which must be thoroughly stirred under, up to the moment of congealing. The soluble glass must also be saturated as much as possible with silicic acid, because a salt which is poor in silicic acid combines but in small proportions with the soap. This soluble glass soap, when made with unbleached palm oil, attains a yellowish color. It often contains (j0 per cent, of soluble glass, and has a tolerable consistency, is not stick}' like rosin soap, is free from the disagreeable smell of the latter, and foams like common soaps. It is deserving of especial mention that these soaps are frequently sold for rosin soaps, although they contain no trace of rosin. The crutching machines illustrated elsewhere are used for the mechanical admixture of the soluble glass and other tilling. Silicated soaps are also a numerous class of soaps now found in all markets under a great variety of names, as sand, crystal, diamond, etc. They are simply a common soap usually containing rosin, as that appears, by its tenacious consistency, to have the power to best hold their" heavy materials. We give several processes. Gossage's Process.—This method consists in the mechanical mixture of soluble glass with the soap paste. The soluble glass is a thick, viscid liquor, made by fusing together, in a reverberatory furnace, 9 parts of 50 per cent, soda ash, with eleven parts of clean sand, or powdered quartz, for hard soaps; or equal weights of dry pearlash and sand, for soft soaps. When the mixture has combined, it is drawn off into moulds, quenched with water, ground in the eccentric mill, and boiled with alkaline water. The solution, when coin- 328 Previous Next
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